The hallmarking of British silver is based on a combination of marks that makes possible the
identification of the origin and the age of each silver piece manufactured or traded in the UK. The marks are:

Town mark, corresponding to the mark of the Assay Office that has verified the piece

Lion passant guardant or Britannia or lion's head erased, certifiying the silver quality

Maker's mark, identifying the silversmith presenting the piece to the assay office (usually the initials of Christian name and surname of the silversmith)
Date letter, in cycles of twenty letters of the alphabet of different shape identifies the year in which
the piece was verified by the Assay Office

A further mark was used in the period 1784 - 1890:
Sovereign head ('duty mark'), certifying the payment of the duty